Portable information technology devices such as smartphones, tablet computers, personal digital assistants (PDAs), and notebook and netbook computers have become widespread. Such electronic apparatus comprise an operation input panel integrated with a display panel.
When a user touches the display surface, the operation input panel detects the touched position as, for example, a change in capacitance. A detection signal associated exclusively with the operation input panel is input to a touch signal processing integrated circuit (IC). The touch signal processing IC processes the detection signal by means of a programmed algorithm, converts the position touched by the user to coordinate data and outputs the data.